Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Food Chem ; 305: 125453, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505417

RESUMO

Impact of glycerol and sorbitol on assembly of iron-bound ovotransferrin (OVT) into nanofibrils was investigated. Thioflavin T fluorescence result indicated that the presence of glycerol or sorbitol could reduce the rate of OVT fibrillation. Sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that 60% sorbitol could retard hydrolysis of OVT completely for a period of time during thermal treatment, and decoupling hydrolysis from fibril self-assembly helped to identify the building blocks of OVT nanofibrils. OVT nanofibrils were composed of both intact OVT monomers and OVT-derived peptides. Influence of glycerol and sorbitol on morphology of OVT nanofibrils was studied using atomic force microscopy. The presence of glycerol or sorbitol shortened OVT nanofibrils, and the presence of 60% glycerol or sorbitol could increase thickness of OVT nanofibrils. Hopefully, this work may provide new insight about building blocks of protein nanofibrils and impact of polyols on protein fibrillation.

2.
Food Res Int ; 125: 108602, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31554072

RESUMO

The present study aimed to investigate protection and bioaccessibility of curcumin in ovotransferrin (OVT) fibril-stabilized Pickering emulsions. Curcumin protection of OVT fibril-stabilized emulsions against ultraviolet light exposure was studied. OVT fibril-stabilized Pickering emulsion at an ionic strength of 1000 mM provided the best curcumin protection. OVT fibril-stabilized Pickering emulsion at pH 6 provided better curcumin protection than those at pH 2 and 4. Afterwards, digestion of OVT fibril-stabilized curcumin emulsion was investigated in both TNO dynamic digestion model (TIM-1) and pH-stat static digestion model. In terms of TIM-1 result, curcumin bioaccessibility in OVT fibril-stabilized emulsion increased by 129% when compared with that in bulk oil. In pH-stat digestion model, curcumin bioaccessibility increased by 114% after formulated into OVT fibril-stabilized droplets, which was due to higher extent of lipolysis. Interestingly, both TIM-1 and pH-stat digestion models gave almost consistent measurements of improved percentage in curcumin bioaccessibility. Curcumin bioaccessibility of the emulsion in TIM-1 and pH-stat model was 15.3% and 33.8% respectively, indicating bioaccessibility overestimation in pH-stat model. The novel findings in this work could facilitate designing food-grade Pickerinng emulsion with excellent nutraceutical protection and enhanced nutraceutical bioaccessibility.

3.
Molecules ; 24(17)2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31443488

RESUMO

As a functional polysaccharide, inulin was carboxymethylated and it formed nanocomplexes with bovine serum albumin (BSA). The success of obtaining carboxymethyl inulin (CMI) was confirmed by a combination of Fourier transform Infrared (FT-IR), Raman spectroscopy, gel permeation chromatography (GPC), and titration. The effects of pH and ionic strength on the formation of CMI/BSA nanocomplexes were investigated. Our results showed that the formation of complex coacervate (pHφ1) and dissolution of CMI/BSA insoluble complexes (pHφ2) appeared in pH near 4.85 and 2.00 respectively. FT-IR and Raman data confirmed the existence of electrostatic interaction and hydrogen bonding between CMI and BSA. The isothermal titration calorimetry (ITC) results suggested that the process of complex formation was spontaneous and exothermic. The complexation was dominated by enthalpy changes (∆Η < 0, ∆S < 0) at pH 4.00, while it was contributed by enthalpic and entropic changes (∆Η < 0, ∆S > 0) at pH 2.60. Irregularly shaped insoluble complexes and globular soluble nanocomplexes (about 150 nm) were observed in CMI/BSA complexes at pH 4.00 and 2.60 while using optical microscopy and atomic force microscopy, respectively. The sodium chloride suppression effect on CMI/BSA complexes was confirmed by the decrease of incipient pH for soluble complex formation (or pHc) and pHφ1 under different sodium chloride concentrations. This research presents a new functional system with the potential for delivering bioactive food ingredients.

4.
J Agric Food Chem ; 67(35): 9907-9915, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31436102

RESUMO

The impact of covalent or non-covalent bound gallic acid (GA) on the formation, physicochemical properties, and digestion of ovotransferrin (OTF) nanofibrils was comprehensively studied. Thioflavin T fluorescence results revealed that bound GA could inhibit OTF nanofibrillation and that the fibril-inhibitory activity of bound GA was dose dependent. Covalent bound GA exerted stronger inhibition on OTF nanofibrillation than an equal amount of non-covalent bound GA. Atomic force microscopy revealed that covalent bound GA shortened OTF nanofibrils significantly, while non-covalent bound GA did not change the contour length of OTF fibrils remarkably. Bound GA altered diameter of OTF nanofibrils. Both covalent and non-covalent bound GA could alter the zeta potential, surface hydrophobicity, and rheological properties of OTF nanofibrils. Bound GA endowed OTF nanofibrils with a strong antioxidant activity. In vitro gastrointestinal digestion results showed that covalent bound GA elevated the fibril digestion rate better than non-covalent bound GA. Polyphenol binding provided a new approach to modulating the physicochemical properties of protein nanofibrils.


Assuntos
Conalbumina/química , Ácido Gálico/química , Nanofibras/química , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Galinhas , Conalbumina/metabolismo , Digestão , Ácido Gálico/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Microscopia de Força Atômica , Modelos Biológicos , Reologia
5.
Food Funct ; 10(8): 4911-4923, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31342040

RESUMO

The present work aimed to fabricate antioxidant particle-stabilized Pickering emulsions with outstanding protection of encapsulated nutraceuticals. Antioxidant ovotransferrin-gallic acid conjugates (OTGCONJ) were prepared using the alkaline method, and the electrostatic assembly technique was utilized to construct OTGCONJ-CMD particles with OTGCONJ and carboxymethyldextran (CMD) as the building blocks. After the investigation of the particle size, insoluble nature and intermediate wettability of the OTGCONJ-CMD particles, the OTGCONJ-CMD particles were verified as eligible Pickering stabilizers. Visual observation showed that the stable OTGCONJ-CMD particle-stabilized Pickering emulsion consisted of the emulsified phase alone. Rheological analysis revealed that the Pickering emulsion had a high viscosity and a gel-like structure. In terms of the protective effect, the OTGCONJ-CMD particle-stabilized Pickering emulsion could significantly retard curcumin degradation under UV light. An in vitro digestion study revealed that the OTGCONJ-CMD particle-stabilized Pickering emulsion improved both the extent of lipolysis and curcumin bioaccessibility remarkably, suggesting that the OTGCONJ-CMD particle-stabilized Pickering emulsion was an excellent nutraceutical delivery vehicle. The novel findings in this work could have important implications for the design of nutraceutical-loaded Pickering emulsions with an excellent protective effect and nutraceutical delivery efficiency.

6.
J Agric Food Chem ; 67(5): 1344-1352, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30640454

RESUMO

Protein-polysaccharide complexes can be created in various ways (physical mixing, enzymatic cross-linking, chemical cross-linking, and Maillard reaction), and diverse protein-polysaccharide complexes are generally grouped into non-covalent and covalent complexes. Delivery systems constructed through assembly of protein-polysaccharide complexes (DSAPC) consist of emulsion-based delivery systems, capsule-based delivery systems, molecular complexes, nanogels, core-shell particles, composite nanoparticles, and micelles. DSAPC are effective delivery vehicles in enhancing the overall efficacy of bioactive ingredients, and DSAPC may possess multiple advantages over other delivery vehicles in bioactive ingredient delivery. However, designing and applying DSAPC are still faced with some challenges, such as low loading of bioactive ingredients. Efforts are required to reconsider and improve efficiency of DSAPC in many aspects, such as controlled release and targeted delivery. On the basis of more comprehensive and deeper understandings, DSAPC can be designed more rationally for delivery of bioactive ingredients.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Polissacarídeos/química , Proteínas/química , Animais , Portadores de Fármacos/química , Humanos
7.
Biomark Med ; 12(10): 1095-1103, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30191731

RESUMO

AIM: To investigate the diagnostic roles of circulating inflammatory biomarkers in gallbladder carcinoma (GBC). PATIENTS & METHODS: Circulating inflammatory cell count, fibrinogen, albumin, carcinoembryonic antigen (CEA) and CA199 were measured, neutrophil-to-lymphocyte ratio (NLR), dNLR, PLR, LMR and Alb-to-fib (AFR) were calculated in 306 GBC patients, 306 healthy and 305 benign controls. The reciever operating characteristic curve was used to determine diagnostic accuracy of them. RESULTS: The area under curves of combined AFR, dNLR and lymphocyte were 0.943 and 0.985 for diagnosis of GBC from healthy and polyp controls, area under curve of combined AFR, CEA and CA199 was 0.90 for diagnosis of GBC from the cholecystitis patients. CONCLUSION: Circulating AFR combined with lymphocyte and dNLR or CEA and CA199 could effectively distinguish GBC from the healthy and benign controls.

8.
Exp Cell Res ; 368(2): 147-158, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29730164

RESUMO

Circular RNAs (circRNAs) are a recently discovered form of RNA. Initially, circRNAs were believed to result from errors during the process of gene transcription. However, after further investigation, scientists suggested that circRNAs are of great biological significance. CircRNAs show stability, conservation, abundance, and tissue and stage specificity. They can also function as miRNA sponges, regulate gene expression, and interact with proteins to affect cell behavior. Emerging evidence has also demonstrated that circRNAs participate or show abnormal expression in diseases, including central nervous system diseases, cardiovascular diseases and cancers, indicating their marked potential in the prediction and prognosis of diseases and clinical treatment.

9.
Future Oncol ; 14(3): 229-239, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29338337

RESUMO

AIM: To investigate diagnostic value of preoperative inflammatory biomarkers in pancreatic cancer (PCC). MATERIALS & METHODS: Preoperative circulating Alb/Fib ratio, neutrophil/lymphocyte ratio (NLR), derived NLR (dNLR), platelet/lymphocyte ratio and lymphocyte/monocyte ratio were detected and calculated in 226 PCC individuals, 232 healthy controls and 142 additional cancer controls. Receiver-operating characteristic curve and area under the curve (AUC) were used to evaluate the diagnostic efficacy of PCC. RESULTS: Combined circulating dNLR and Alb could effectively improve the diagnosis of PCC (AUC = 0.931), single dNLR could distinguish early-stage PCC and the disease from healthy controls (AUC = 0.895) and additional cancer controls (AUC = 0.794). CONCLUSION: Circulating dNLR was an effective biomarker for diagnosis and identification of early-stage PCC. Combined dNLR and Alb could improve the diagnostic efficacy of the disease.


Assuntos
Mediadores da Inflamação/sangue , Contagem de Leucócitos , Linfócitos , Neutrófilos , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Estudos de Casos e Controles , Detecção Precoce de Câncer , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias Pancreáticas/cirurgia , Período Pré-Operatório , Prognóstico , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade
10.
Cell Death Dis ; 8(9): e3035, 2017 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-28880263

RESUMO

Oral squamous cell carcinoma (OSCC) is a leading cause of cancer-related deaths worldwide, with 500 000 new cases each year. However, the mechanisms underlying OSCC development are relatively unknown. In this study, matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS)-based proteomic strategy was used to profile the differentially expressed peptides/proteins between OSCC tissues and their adjacent noncancerous tissues. Sixty-seven unique peptide peaks and five distinct proteins were identified with changed expression levels. Among them, LRP6 expression was found to be upregulated in OSCC tissues, and correlated with a cluster of clinicopathologic parameters, including smoking, drinking, tumor differentiation status, lymph node metastasis and survival time. Notably, knockdown of LRP6 inhibited the proliferation ability of OSCC cells. Furthermore, we demonstrated that the expression of LRP6 in OSCC cells is positively correlated with its downstream oncogene, FGF8. The present study suggests that LRP6 could be a potential biomarker for OSCC patients, and might further assist in the therapeutic decisions in OSCC treatment.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Neoplasias Bucais/genética , Proteínas de Neoplasias/genética , Consumo de Bebidas Alcoólicas/fisiopatologia , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Fumar Cigarros/fisiopatologia , Fator 8 de Crescimento de Fibroblasto/genética , Fator 8 de Crescimento de Fibroblasto/metabolismo , Humanos , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Metástase Linfática , Neoplasias Bucais/diagnóstico , Neoplasias Bucais/mortalidade , Neoplasias Bucais/patologia , Proteínas de Neoplasias/metabolismo , Estadiamento de Neoplasias , Prognóstico , Proteoma/genética , Proteoma/metabolismo , Fatores de Risco , Transdução de Sinais , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Análise de Sobrevida
11.
Int J Biol Macromol ; 105(Pt 1): 912-923, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28743571

RESUMO

Stem lettuce is widely consumed as a vegetable in China. It is also used as a traditional Chinese medicine for a long time. Up to now, no information is available for stem lettuce polysaccharide (SLP). In this study, extraction optimization, characterization, and antioxidant activity of SLP was investigated.The maximum SLP yield of 20.89% was obtained under the optimal extraction conditions as follows: extraction temperature 95°C, extraction time 3.3h and ratio of water to material 25mL/g. The sulfate content of SLP was 5.82% and the main monosaccharides were GalA, Gal, and Ara with a mole ratio of 49.2: 23.3: 22.9. FT-IR spectrum and HPGPC result further indicated that SLP is a sulfated polydisperse heterpolysaccharide. Congo-red test and AFM scan indicated that SLP might be branching and intertwining structure with triple helix conformation. Moreover, SLP exhibited potent antioxidant activity and α-amylase inhibitory activity, hence it could be used as a potential natural antioxidant and hypoglycemic agent in medicine or functional food fields.


Assuntos
Fracionamento Químico/métodos , Alface/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Água/química , Amilases/antagonistas & inibidores , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Monossacarídeos/análise , Polissacarídeos/química , Solubilidade , Sulfatos/química
12.
Oncotarget ; 8(2): 2141-2152, 2017 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-27924064

RESUMO

Precision medicine is a new strategy that aims at preventing and treating human diseases by focusing on individual variations in people's genes, environment and lifestyle. Precision medicine has been used for cancer diagnosis and treatment and shows evident clinical efficacy. Rapid developments in molecular biology, genetics and sequencing technologies, as well as computational technology, has enabled the establishment of "big data", such as the Human Genome Project, which provides a basis for precision medicine. Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer with a high incidence rate and low survival rate. Current therapies are often aggressive and carry considerable side effects. Much research now indicates that precision medicine can be used for HNSCC and may achieve improved results. From this perspective, we present an overview of the current status, potential strategies, and challenges of precision medicine in HNSCC. We focus on targeted therapy based on cell the surface signaling receptors epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and human epidermal growth factor receptor-2 (HER2), and on the PI3K/AKT/mTOR, JAK/STAT3 and RAS/RAF/MEK/ERK cellular signaling pathways. Gene therapy for the treatment of HNSCC is also discussed.


Assuntos
Carcinoma de Células Escamosas/terapia , Neoplasias de Cabeça e Pescoço/terapia , Medicina de Precisão/tendências , Animais , Humanos , Sistema de Sinalização das MAP Quinases , Terapia de Alvo Molecular , Fosfatidilinositol 3-Quinases/metabolismo , Medicina de Precisão/métodos , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/metabolismo , Fator de Transcrição STAT3 , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço , Serina-Treonina Quinases TOR/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
13.
Int J Biol Macromol ; 86: 376-82, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26820353

RESUMO

The objectives of the present study were to first synthesize chitosan-chlorogenic acid (CA) covalent complex and then compare structural and functional properties between chitosan-CA covalent complex and physical complex. First, chitosan-CA covalent complex was synthesized and its total phenolic content was as high as 276.5 ± 6.2 mg/g. Then structural and functional properties of chitosan-CA covalent and physical complexes were analyzed. The covalent reaction induced formation of both amide and ester bonds in chitosan. Data of X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicated that the complexations of CA changed crystallinity and morphology of chitosan, and covalent complexation induced a larger change of physical structure than physical complexation. In terms of functional properties, chitosan-CA covalent complex exhibited better thermal stability than physical complex in terms of antioxidant activity, and the viscosity of chitosan was significantly increased by covalent modification.


Assuntos
Quitosana/química , Ácido Clorogênico/química , Ácido Clorogênico/síntese química , Estabilidade de Medicamentos , Depuradores de Radicais Livres/síntese química , Depuradores de Radicais Livres/química , Reologia , Temperatura Ambiente
14.
Food Chem ; 173: 564-8, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25466060

RESUMO

In this study the impact of covalent complexes of α-lactalbumin (α-La) with (-)-epigallocatechin gallate (EGCG) or chlorogenic acid (CA) was investigated on the physicochemical properties of ß-carotene oil-in-water emulsions. EGCG, or CA, was covalently linked to α-La at pH 8.0, as evidenced by increased total phenolic content and declined fluorescence intensity. Compared with those stabilised by α-La alone and α-La-CA or EGCG mixture, the emulsion stabilised by the α-La-EGCG covalent complex exhibited the least changes in particle size and transmission profiles, using a novel centrifugal sedimentation technique, indicating an improvement in the physical stability. The least degradation of ß-carotene occurred in the emulsion stabilised with the α-La-EGCG covalent complex when stored at 25 °C. These results implied that protein-polyphenol covalent complexes were able to enhance the physical stability of ß-carotene emulsion and inhibit the degradation of ß-carotene in oil-in-water emulsion, and the effect was influenced by the types of the phenolic compounds.


Assuntos
Catequina/análogos & derivados , Ácido Clorogênico/química , Emulsões/química , Lactalbumina/química , beta Caroteno/química , Catequina/química , Fenômenos Químicos , Estabilidade de Medicamentos , Tamanho da Partícula , Espectrometria de Fluorescência
15.
J Agric Food Chem ; 60(46): 11592-600, 2012 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-23121318

RESUMO

The objective of this research was to fabricate novel antimicrobial films based on zein colloidal nanoparticles coated with sodium caseinate (SC), an emulsifier/stabilizer. Thymol-loaded zein-SC nanoparticles were prepared using an antisolvent technique, with the average particle size and zeta potential about 200 ± 20 nm and -40 mV, respectively. Zein-SC nanoparticle-based films exhibited higher mechanical resistance and water barrier capacity than the SC films and concomitant good extensibility as compared with zein films. Thymol loadings endowed zein-SC nanoparticle-based films with antimicrobial activity against Escherichia coli and Salmonella as well as DPPH radical scavenging activity. Water vapor permeability, microstructure, mechanical, and controlled release properties of the films were evaluated. The possible relationship between some selected physical properties and microstructure were also discussed. Atomic force microscopy (AFM) analysis indicated that thymol loadings resulted in the emergence phenomena of the nanoparticles to form large particles or packed structure, consisting of clusters of nanoparticles, within the film matrix, in a thymol loading dependent manner. The appearance of large particles or an agglomerate of particles may weaken the compactness of protein network of films and thus impair the water barrier capacity, mechanical resistance, and extensibility of the films. The release kinetics of thymol from nanoparticle-based films can be described as a two-step biphasic process, that is, an initial burst effect followed by subsequent slower release, and zein-SC nanoparticles within the films matrices gave them the ability to sustain the release of thymol. In addition, a schematic illustration of the formation pathway of zein-SC nanoparticle-based films with or without thymol was proposed to illuminate the possible relationship between some selected physical properties and the microstructure of the films.


Assuntos
Antibacterianos/química , Caseínas/química , Embalagem de Alimentos/instrumentação , Extratos Vegetais/química , Timol/química , Zeína/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Extratos Vegetais/farmacologia , Salmonella/efeitos dos fármacos , Timol/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA